Organize add-on scripts into subdirectories

addon/dialog/dialog.css

addon/dialog/dialog.js

addon/edit/closetag.js

addon/edit/continuecomment.js

addon/edit/continuelist.js

addon/edit/matchbrackets.js

addon/fold/collapserange.js

addon/fold/foldcode.js

addon/format/formatting.js

addon/hint/javascript-hint.js

addon/hint/pig-hint.js

addon/hint/python-hint.js

addon/hint/simple-hint.css

addon/hint/simple-hint.js

addon/hint/xml-hint.js

addon/mode/loadmode.js

addon/mode/multiplex.js

addon/mode/overlay.js

addon/runmode/colorize.js

addon/runmode/runmode-standalone.js